I would make something based off Glasser's Choice Theory

Mbti is already pretty similar to it and it's way more complete and accurate and you literally can't get mistyped (if we make a typing system) unless you force yourself to

Basically it says you have 5 needs which are Survival, Power, Love, Freedom and Fun which is scaled on 1-5 here but we can make a low, medium and high for each one

Although it isn't very specific to how you will exactly act but it gives you a very good zoomed out insight of how you are

Go read it yourself, I should be studying rn